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Evaluation of Balance
Published in R James A England, Eamon Shamil, Rajeev Mathew, Manohar Bance, Pavol Surda, Jemy Jose, Omar Hilmi, Adam J Donne, Scott-Brown's Essential Otorhinolaryngology, 2022
Vertigo is a reliable vestibular symptom, but lesions can be anywhere from the semicircular canals to vestibular cortex. Additional symptoms allow localisation (Table 5.1). Duration is indicative, lasting seconds in benign paroxysmal positional vertigo (BPPV); minutes to many hours in migraine-associated vertigo (vestibular migraine); a few hours in Meniere's disease; and days in acute vestibular neuritis and stroke.
Inflammatory Disorders of the Nervous System
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Sensation of rotation or spinning, causing nausea and ataxia (intra-axial vestibular nerve, vestibular nucleus in the lateral medulla, and pathways from the vestibular nucleus to the vestibular cortex), rarely in isolation and often occurring together with other brainstem symptoms.
Physiology of Equilibrium
Published in John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed, Paediatrics, The Ear, Skull Base, 2018
Floris L. Wuyts, Leen K. Maes, An Boudewyns
The insular cortex is a part of the cerebral cortex folded deep within the lateral sulcus and is believed to have a main role in the processing of vestibular signals.48,49 Moreover, a predominant role of the right hemisphere in the cortical processing of vestibular afferents has also been proven in the meta-analysis by zu Eulenburg et al. 47 More specifically, zu Eulenburg et al. suggest that operculum parietale 2, a histological defined part of the human parietal operculum in the right hemisphere, is the core region of the human vestibular cortex and possibly processes only vestibular information instead of multisensory input. Recently, changes in the vestibular cortex have been shown in an astronaut returning from space.50 Space is a unique lab to investigate the effect of unusual physiological stimuli on the human body such as weightlessness. These preliminary findings corroborate the concept of neuroplasticity and may guide further research to find possible causes in the brain of vestibular disorders such as visual vestibular mismatch among others. Until recently, many vestibular dysfunctions were traditionally attributed to peripheral vestibular lesions, but the brain will become more and more important in vestibular physiology.
Assessing lesion location, visual midline perception and proprioception may assist outcome predictions for people affected by lateropulsion
Published in Disability and Rehabilitation, 2023
The central processing of vestibular inputs commences in the vestibular nucleus which is located in the medulla and pons. Ipsilateral inputs then ascend the brain stem bilaterally as they travel to the posterolateral and paramedial nuclei of the thalamus. The first location of multisensory integration is between the vestibular and visual systems in the superior collicuili of the midbrain, where the vestibulo-ocular reflex is mediated. Another location of multisensory integration is the posterolateral nucleus of the thalamus where both vestibular and proprioceptive inputs converge. From the thalamus, vestibular inputs travel to the non-dominant parieto-insular-vestibular cortex which testifies to lateralisation in the cortical processing of vestibular inputs [6]. Vestibular inputs also travel to the cerebellum, thus a large portion of cerebellar lesions can also manifest as lateropulsion [7].
Central vestibular dysfunction: don’t forget vestibular rehabilitation
Published in Expert Review of Neurotherapeutics, 2022
Sulin Zhang, Dan Liu, E. Tian, Jun Wang, Zhaoqi Guo, Weijia Kong
Pathogenesis of VM is still poorly understood and researchers fail to agree regarding whether its origin is predominantly central or peripheral. The factors involved in the pathogenesis of VM do not work separately but are intricately interwoven [81,82]. Abnormal sensory modulation or integration within the thalamo-cortical network could result in dizziness and spatial disorientation, which may lead to a ‘higher level’ dysfunction of the multisensory integration function of spatial orientation. Activities such as ballet dancing and yoga can enhance spatial perception and physical coordination [64]. Cortical spreading depression hypothesis assumes that, during aura migraine, various factors stimulate the cerebral cortex and then the inhibitory cortical electrical activity spreads from the stimulation site to the surrounding regions. Vestibular connections can be divided into downward-projecting vestibulospinal tracts and upward projections [i.e. to the ocular motor nuclei that organize the VOR] [83]. When it diffuses to the vestibular cortex (the parietal lobe and insular lobe), the activity is inhibited, and the inhibitory effect on the brainstem vestibular nucleus is weakened, thereby affecting the processing of vestibular signals and causing vestibular symptoms, or leading to transient vestibulo-ocular dysfunction or vestibular hypersensitivity associated with migraine [84].
Current perspectives on galvanic vestibular stimulation in the treatment of Parkinson’s disease
Published in Expert Review of Neurotherapeutics, 2021
Soojin Lee, Aiping Liu, Martin J. McKeown
Animal and human studies have identified that several cortical areas, including the parieto-insular vestibular cortex (PIVC), temporo-parietal junction (TPJ), anterior parietal somatosensory cortex, ventro-intraparietal cortex, and parahippocampal gyrus, are activated during stimulation of the vestibular system [78]. The PIVC is considered to be the principal vestibular cortex because around 1/3 of its neurons respond to vestibular stimulation [23] and have direct efferent projections to the vestibular nuclei [79]. In addition to vestibular stimulation, neurons in the PIVC and TPJ are also activated by somatosensory stimuli from the head, trunk, touch, and vision [79]. Integrating the cues from the environment as well as from within the body, the PIVC and TPJ play roles in generating perceptions of self-motion and body representation in space as well as visuospatial cognitive abilities. Some of these functions might be affected in PD patients, as vestibular deficits in the form of impaired vestibulo-spinal and vestibulo-ocular reflexes [71] as well as the perception of self-motion that requires multisensory (visual and vestibular) integration [80] have been reported.